Impulse-dial apparatus for automatic telephone systems



Nov. 13, 1928.

' W. KRUSE IMPULSE DIAL APPARATUS FOR AUTOMATIC TELEPHONE SYSTEMS Fig. 2

Filed April 7, 1927 feleohone I ,Jm/enmp.

I Wf/he/ r'ulse y Attorney Patented Nov. 13, 1928'.

UNITED STATES I 1,691,575 PATENT OFFICE.

'WHTJHELM IKIBIIJ'SE, OF BERLIN, GERMANY.

IMPULSE-DIAL APPARATUS FOR AUTOMATIC TELEPHONE SYSTEMS.

Application filed April 7, 1927, Serial No. 181,684, and in Germany April 10, 1928.

services and more particularly those a apted' 'for automatic telephones, inscribed with numerals, letters or other indications so arranged as to enable the combination of said numerals or indications to be made as will constitutethecall of the'required subscriber.

It frequently occurs in practice, however,

.that it is required to use such dials with mixed automatic and manual systems, and

an object of the present invention is to permit such a use in a simple and inexpensive manner with a single dlal.

It also occurs 1n practice that it is re.-

' quired to restrict the use of the dial or portion or [portions thereof until certain preliminary conditions are fulfilled by the caller, such as the prepayment of the amount of the call in a coin-collecting box.

To this end the external appearance or construction of the dial, the arrangement of the numerals orindications thereon, and general mechanical features are or may be unchanged or may be of any convenient form, but there is an additional contact system associated therewith for the particular objects in view and constituting the special feature of my present invention.

According to this specialfeature of my invention in the use of the dial, when requiring prepayment to enable a calling sub-. scriber to be placed in communication with a called subscriber, or in the case of a subscribers meter requiring the registration of the call by mechanical means such. as'pressing a button, the usual dial contacts are normally short-circuited or restricted, in some way, or the dial is not introduced into the circuit until such payments or operations. are effected, as by the necessary coin or coins, press button and the like closing or opening contacts which will remove the restrictions, the usual range of indications or so many of them as may be determined being then available for such calls. However,

should it be desired to allow, a signal to pass over the line without prepayment, for example when it is required to call the exchange for manual or non-automatic long distance communication, or to give an alarm for fire,police or other call of an emergency character, I provide .an additional mechanism associated with an impulse dial apparatus which enables the short-circuit of the dial impulse contacts to be restricted for the particular combinations of numerals or indications being provided for calls requiring no payment as stated, and which enables this short-circuit to be effected only for calls of normal character for calling a subscriber and alfording a pre ayment. For instance, I may, according to the mechanism I provide according to my invention,

in a telephone service having 100,000 subscribers i. e, requiring six consecutive num-' bers or indications to be dialled by a person calling a subscriber, send out up to five numbers or indications without payment for calling public stations of the character mentioned, whereas when dialling the 6th number or indication the impulse contacts of the calling device become automatically short-circuited thereby authorized use of the to ephone apparatus the short-circuit of the impulse contacts 0 the dial becomin ping a coin or coins into the collecting box. The latter being done a 6th number or indication may be dialled and a corresponding subscriber be called. In exchanges with reventing an un-' only restricted by dropgreater or smaller numbers of subscribers the same action as stated may be obtained, the number of numerals or indications or of sets of impulses to be sent out without payment being always smaller at least of one than the number of numerals or indications necessary to call a subscriber in that particular telephone service. To, this end, according to a special mode of execution of my invention, I provide a pawl and ratchet mechanism associated with the impulse dial, the ratchet being moved further by one tooth 'by'the execution of one set of impulses i. e.

by each turning of the impulse dial disc.

The ratchet is provided with an extension or pin which after a distinct number of movements by one ratchet tooth actuates a spring contact short-circuiting the 'impulse pulse ,dial and. mechanism embodying my,

invention.

Figure 2 is an end elevation of the same, showmg more particularly the dialing mechamsm.

Figure 3 is a view similar to Figure 2 but showing the general organization including the coin prepayment means.

Figure 4 is a side elevation similar to Figure 2 but showing parts omitted from the latter. Figure 5 is a diagram of the electric circuit.

Equal reference characters in both figures refer to equal parts. In the drawings the mechanism substantially known and adaptable for use in the usual manner for automatic operation when the dial is moved from normal position according to any of the indications to transmit sets of impulses over the line according to the subscribers number to be called, is not shown in the drawing for-simplicitys sake as being out of scope of the present invention and may be of any one of the known structures.

To now turn to the improvements of my invention referring to the drawings 1 is an operating lever which is moved with each turning of the dial disc 2 having holes 3 and arranged in front of the dial bearing the numerals or indications, into which holes the caller has to insert his finger corresponding to the number or indications of the wanted line consecutively and rotate the finger disc until it is stopped by a finger stop and then withdraw the finger again and repeat the same process until the complete number of digits has been dealt with.

With each dialling with a digit i. e. sending out a set of corresponding impulses into the line the operating lever 1 moves forward a ratchet wheel 4 by one of its teeth against the action of a spring 5 anchored at the one hand on that ratchet wheel and on the other hand on a spindle 6 which serves as an axis for the rotation of the ratchet wheel.

The ratchet wheel is held in its position byv a pawl spring 7 After the ratchet wheel 4 has been moved a distinct number of steps,

' a contact mechanism 8 short circuiting the impulse contacts of the calling device is operated by a pin 9 fixed on the ratchet wheel. The whole apparatus may be released by a lever 10 moving the ratchet wheel in the direction of its axis and thereby disengagingthe spring 7 and operating lever 1. The pin 9 may be so arranged on the ratchet wheel that it is possible to send out any number of sets of impulses smaller than the number of the sets of impulses necessary to call a subscriber in the change these combinations 0 impulses being at ributed to the public places mentioned and intended to require no payment for calling, in contrast to devices hithertoknown, wherethere was only provided one indication namely 0 for-this purpose. (The articular exshort circuit of the impulse contacts may be prevented by prepayment i. e. dropping a coin or coins into the collecting box, whereby a' contact mechanism is operated being in series with the contacts 8 and releasing the impulse contacts of the apparatus. The following is descriptive of the construction and operation of the device applying particularly to the prepayment means fully shown in Figures 3, 4 and 5: a When dialing the number disk is rotated as previously described. On the return movement of the disk the toothed wheel 13 is taken along and thereby the worm 14. rotated. To the worm 14 is fixed at one end a speed regulator 15 and at the other end a disk of insulating material 12; On each revolution of the worm the disk 12 interrupts the impulse contact 11. Simultaneously with the actuation of the disk the device is actuated by the lever 1, as hereinbefore described.

The current circuit is shown in Figure 5.

impulse contact, by the contact 17, to suppress the cracking noises of the selector impulses in the telephone. In Figures 1 to 4, inclusive, thisconta'ct 17 is not shown, since this is a conventional feature. contact 8 is closed by the wheel 4, the impulse contact is short-circuited and the selecting impulses remain inefiective. In the circuit of contact 8 there is a switch, schematically indicated at 21, which allows of the releasing of the short circuit by the introduction of a coin, as shown, but any suitable means. may be provided for this purpose.

It may be remarked that on laying down the receiver the lever 16 is depressed whereby the lever 10 (Figs. 2 and 4) is moved toward the right, causing the toothed wheel 4 to be displaced toward the left and is returned into its normal position, i. e., in contact with pin 9 .by the spring 5.

What I claim to be secured by Letters Patent of the United States is v1. An impulse dial apparatus for tele-.

phone systems of the character described comprising in combination means. adapted to send out a consecutive number of sets of impulses-according to special indications for calling a particular subscriber, a step-by-step If now mechanism associated with said .dial appaa spring contact tacting mechanism after a distinctnumber of sets of impulses has been sent out. a

2. An impulse dial a paratus for telephone systems of the character described comprising in combination an impulse c0ntact mechanism adapted to send into the line a consecutive number of sets of impulses to operate the switching apparatus in the exchange according to special indications for calling a particular subscriber, a pawl and ratchet mechanism associated with said impulse dial apparatus for turning said ratchet wheel a step with each sending out of a set of impulses a springcontact, a member on said ratchet wheel "for operatin said sprin contact 'short-circuiting the impulse contacts of the dial apparatus and prepayment concontact after a distinct num er of" sets 0 impulses has been sent out, sald spring.

mechanism adapted to send into the line a consecutive number of sets of impulses to o erate the switching apparatus in the exc ange accord' to special indications marked on the dlal for calling a particular subscriber, a pawl and ratchet mechanism associated with said impulse dial apparatus for moving said ratchet wheel by one tooth with each sending out of a set of impulses a projection upon said ratchet wheel, a. spring contact operated bfy said Projection after a distinct number 0 sets 0 impulses or movements of the ratchet wheel has been carried out, said spring contact short-circuiting the impulse contacts of the dial apparatus, prepayment controlled means to restrict said short circuit of said impulse con-. 40-

have 'afiixed my signature.

y KRUSE. 

